Stephen Schroeder figured he had little to lose, his growing sense of desperation fueled by the loneliness of his unusual diagnosis.

For more than two years, Schroeder had been coping with an extremely rare, invasive cancer called extramammary Paget’s disease (EMPD), which had invaded his scrotum, requiring multiple surgeries. Women account for roughly half of EMPD cases; the cancer, often misdiagnosed as eczema or contact dermatitis, attacks the sweat-producing apocrine glands, including those in the genital and anal areas.

The slow-growing cancer, which in men is frequently misdiagnosed as “jock itch” — slang for a fungal infection — can be fatal. And while treatment is often grueling, for Schroeder the worst part was his sense of isolation: He had never spoken to anyone who shared his diagnosis.

But in time Schroeder would engineer a solution to his isolation, reaping its benefits by connecting with others in similar circumstances. The richness of that experience, he said, has exceeded anything he could have imagined.

In 2016, after his second recurrence, Schroeder set up a Web page hoping to find other patients to talk to; only a few hundred cases of EMPD have been reported worldwide. Earlier he had told doctors who had treated him in Seattle, Philadelphia and Manhattan — all of whom were treating other EMPD patients — that he wanted them to share his contact information, hoping someone might get in touch.

Disappointingly, his efforts were met with radio silence.

Breaking the silence

So later that year, against the wishes of his wife and three grown children, Schroeder, director of membership development for a purchasing cooperative based in the Pacific Northwest, went public. His case appeared in the Medical Mysteries column.

In the weeks following publication, Schroeder said he received hundreds of emails. So far, 72 people diagnosed with EMPD — most from the United States and about half of them women — have contacted him to share their stories and trade information about treatments, doctors and coping strategies. Most have joined the international online support group that Schroeder formed. Nearly all told him that until his case was published, they had never known anyone else with EMPD even though they knew such people existed.

Schroeder, now 58, spends about eight hours a week engaged in what he calls “my new passion”: networking with patients around the world, firing off notes of support to the newly diagnosed or to those facing surgery, and ensuring that his website, which has recorded traffic from 73 countries, is running smoothly. He has also fielded queries from cancer researchers.

One team of urologists used data provided by members of Schroeder’s support group in a recent study, which scientists hope will generate new research into the rare disorder.

Schroeder, who lives in Spokane, Wash., and travels often for work, has met a dozen of the patients who contacted him, encounters he characterized as among the most meaningful of his life.

“I can’t explain what it’s like to meet a stranger and then within hours or days you have a deep connection,” he said.

Pushing for a diagnosis

Dave Ross, chief technology officer for a San Diego firm, was flying back from China in October 2016 when he read Schroeder’s story in a newspaper passed out by a flight attendant. “I’m not sure why I took it,” Ross said. “I never read newspapers. But I did that day.”

The engineer, then 50, grew uneasy as he perused Schroeder’s account, which sounded eerily similar to his own experience. Six months earlier Ross had consulted a dermatologist for what he was told was persistent jock itch. The doctor had given him a prescription cream, but the quarter-size itchy red patch remained.

Ross decided that when he got home, he would press his dermatologist to biopsy the site, just as Schroeder had done. Ross also contacted Schroeder, using the information on his website as the basis for questions he asked doctors.

“There was more information available from Steve than there was online,” Ross said. “I’m just so lucky I saw his story.”

The biopsy showed what Ross had feared: EMPD, not the squamous cell cancer one dermatologist had initially suspected. The recommended treatment was Mohs surgery. The procedure involves removing thin layers of skin and examining each one under a microscope until no malignancy is detectable.

Ross, who had been adopted as an infant, called his birth mother whom he’d tracked down as an adult, with the news. “She told me, ‘Oh, I had that when I was about your age,’ ” Ross recalled. Some researchers suspect the disease may have a familial link.

A few days before his February 2017 operation, Ross said, a member of the fledgling support group who had been battling EMPD for several years, died of the disease. “The diagnosis scared me so bad,” Ross recalled. He is being monitored regularly, and his cancer has not recurred.

In the past year Ross and Schroeder have become friends, meeting twice for meals while Schroeder was in Southern California on business.

Pattee Carroll, a 66-year-old insurance company account manager who lives in Phenix City, Ala., found Schroeder’s story compelling. Carroll underwent surgery for EMPD in 2015 but had never spoken to anyone with the disease until she emailed Schroeder soon after reading his story.

“Just to know there are other people out there to talk to and things being done makes me feel better,” she said. But Carroll said she largely avoids the support group. “It caused me more worry and concern.”

A catalyst for research

To Bryan Voelzke, an associate professor of reconstructive urology at the University of Washington School of Medicine in Seattle, Schroeder is first and foremost a patient. Voelzke has performed several surgeries on Schroeder, who moved from the Philadelphia area back to his native Spokane after his 2014 diagnosis.

The patient contacts that Schroeder has amassed have also proved invaluable to the research undertaken by Voelzke and his colleagues. Because EMPD is so rare, Voelzke said, most studies of the disease have involved only a relative handful of patients treated at a single hospital, usually in Asia.

But the number of American patients who contacted Schroeder, coupled with an increased emphasis on patient-centered outcomes and evidence-based choices that is part of the Affordable Care Act, presented an unusual opportunity to study the demographics of EMPD diagnosis and treatment. In a matter of months, Schroeder had single-handedly amassed what appears to be the largest known group of American patients; they had been treated by a variety of specialists at multiple institutions.

Schroeder agreed to grant access to his support group, and Voelzke’s team received approval for the study from the ethics board at the University of Washington. In January, researchers emailed a survey to 55 patients, 75 percent of whom completed it.

Their study, published in the journal Urology, found that the average case was diagnosed about 21 months after symptoms first appeared. Patients were treated by a wide variety of specialists — gynecologists, surgeons, dermatologists, urologists — and received multiple treatments ranging from Mohs surgery to the use of a prescription cream approved to treat genital warts. About 30 percent of those surveyed suffered a recurrence, including spread of the cancer to a distant part of the body, which typically occurs quickly and can prove fatal.

Voelzke said he hopes publication of the study will spur the development of standardized treatments for EMPD and accelerate “knowledge dispersal” among doctors and patients.

For Schroeder, the past year has also brought good news about his own health.

After his recurrences, each of which was followed by arduous surgeries and skin grafts, Schroeder’s cancer has been in remission for more than a year.

His activism, he said, has generated one of the things he wanted most: contact with others who share the same diagnosis.

“As a result of this, I’ve met people I never would have met in a hundred years,” he said. “I went from being totally isolated, fighting this battle by myself in a vacuum, to finding all these new friends.”